package 第168场.B;
// 不要把package复制进答案里
//--------------------------------------------

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

/**
 * 通过
 */
public class Main {
    public static void main(String[] args) throws IOException {
        BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
        String line = in.readLine();
        int k = Integer.valueOf(line);
        String s = in.readLine();

        if (s.length() > k) {
            String temp = s.substring(0, k);
            System.out.println(temp + "...");
        } else {
            System.out.println(s);
        }
    }
}
